Surgical management of rectal cancer: a multidisciplinary approach to technical and technological advances

Evaluation of lateral pelvic nodes in patients with advanced rectal cancer. AJR Am J Roentgenol. 2014;202:1245-1255. [PMID: 24848821 DOI: 10.2214/ajr.13.11228]

OBJECTIVE

The purpose of this article is to discuss the importance of lateral pelvic lymph node metastasis as a predictor of local recurrence and survival in patients with advanced rectal cancer.

CONCLUSION

Prediction of lateral pelvic nodal staging on MRI shows high accuracy compared with the other imaging modalities. Diffusion-weighted MRI or (18)F-FDG PET/CT may be helpful to assesses lateral pelvic lymph node metastasis.

Single versus double stapling anastomotic technique in rectal cancer surgery

PURPOSE

The present study was designed to investigate whether there is a difference in the anastomotic leakage rate (AL) between the single stapling (CSA) and double stapling (DSA) anastomosis techniques.

METHODS

One hundred consecutive rectal cancer patients who underwent rectal resection with primary anastomosis were enrolled in this study.

RESULTS

The overall rate of clinical anastomotic leakage in both groups was 7 % (7/100); 6 % (3/50) in the CSA group and 8 % (4/50) in the DSA group. The anastomotic technique did not have any significant influence on the rate of AL. All AL were seen in low anastomoses (7 cm and below). The rate of AL in patients with a diverting stoma (13 %, 3/23) was not significantly different from that of the patients without (5.2 %, 4/77) (p = 0.195). The mean length of the operation was significantly shorter in the DSA group compared to the CSA group, at 127 and 141 min, respectively (p = 0.005). There were significantly higher rates of AL in patients receiving preoperative long course radiotherapy (15.4 %, 6/39) compared with those who did not receive radiotherapy (1.63 %, 1/61) (p = 0.014).

CONCLUSIONS

The CSA and DSA techniques are equally safe for the creation of a rectal anastomosis, without any significant difference in the AL rate. However, we recommend using the DSA technique because it has other definite advantages. In cases of neoadjuvant treatment and a low anastomosis, proximal diversion is recommended.

Diffusion-weighted imaging in rectal carcinoma patients without and after chemoradiotherapy: a comparative study with histology

Diffusion-weighted imaging (DWI) can be used to quantitatively assess functional parameters in rectal carcinoma that are relevant for prognosis and treatment response assessment. However, there is no consensus on the histopathological background underlying the findings derived from DWI. The aim of this study was to perform a comparison of DWI and histologic parameters in two groups of rectal carcinoma patients without (n=12) and after (n=9) neoadjuvant chemoradiotherapy (CRT). The intravoxel incoherent motion (IVIM) model was used to calculate the diffusion coefficient D and the perfusion fraction f in rectal carcinoma, the adjacent rectum and fat in the two patient groups. Immunohistological analysis was performed to assess the cellularity, vascular area fraction and vessel diameter for comparison and correlation. Out of 36 correlations between parameters from DWI and histology, four were found to be significant. In rectal carcinoma of patients without CRT, the diffusion D and the perfusion f correlated with the vascular area fraction, respectively, which could not be found in the group of patients who received CRT. Further correlations were found for the rectum and fat. Histological evaluation revealed significant differences between the tissues on the microscopic level concerning the cellular and vascular environment that influence diffusion and perfusion. In conclusion, DWI produces valuable biomarkers for diffusion and perfusion in rectal carcinoma and adjacent tissues that are highly dependent of the underlying cellular microenvironment influenced by structural and functional changes as well as the administered treatment, and consequently can be beyond histological ascertainability.

Preoperative decision making for rectal cancer

BACKGROUND

Rectal cancer treatment has become multimodal as a result of significant advances in imaging, staging, surgery, radiotherapy, and chemotherapy. Multidisciplinary teams can incorporate these developments into tailor-made treatment plans and offer state-of-the-art services for rectal cancer patients.

METHODS

We searched the MEDLINE and PubMed databases using the following keywords: "rectal cancer," "total mesorectal excision," "multidisciplinary treatment/team," "radiotherapy," "chemotherapy," and their combinations. There were no language or publication year restrictions. References in published articles also were reviewed.

RESULTS

Total mesorectal excision surgery, high-resolution pelvic magnetic resonance imaging, preoperative chemoradiotherapy, and pathologic reports according to Quirke protocol are preconditions for the initiation of an effective multidisciplinary team. Common topics for discussion are the status of the circumferential margin, the type of radiotherapy and surgery required, and the chemotherapeutic agent to be used.

CONCLUSIONS

This review focuses on this issue based on two main principles. First, the status of the circumferential margin dictates the use of preoperative chemoradiotherapy. Second, preoperative chemoradiotherapy is superior in terms of free circumferential resection margin rate, local recurrence rate, and toxicity.

[Preoperative staging of rectal cancer]

Accurate preoperative staging of rectal cancer is crucial for therapeutic decision making, as local tumor extent, nodal status, and patterns of metastatic spread are directly associated with different treatment strategies. Recently, treatment approaches have been widely standardized according to large studies and consensus guidelines. Introduced by Heald, total mesorectal excision (TME) is widely accepted as the surgical procedure of choice to remove the rectum together with its enveloping tissues and the mesorectal fascia. Neoadjuvant radiochemotherapy also plays a key role in the treatment of locally advanced stages, while the use of new drugs will lead to a further improvement in oncological outcome. Visualization of the circumferential resection margin is the hallmark of any preoperative imaging and a prerequisite for high-quality TME surgery. The aim of this article is to present an overview on current cross-sectional imaging with emphasis on magnetic resonance imaging. Future perspectives in rectal cancer imaging are addressed.